/* mpi-internal.h  -  Internal to the Multi Precision */

#ifndef G10_MPI_INTERNAL_H
#define G10_MPI_INTERNAL_H
#ifdef __KERNEL__
#include <linux/string.h>
#include <linux/printk.h>
#include <linux/errno.h>
#else
#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#endif
#include "mpi.h"

#ifdef __KERNEL__
#define mpi_log printk
#else
#define mpi_log printf
#endif

#ifndef __KERNEL_DIV_ROUND_UP
#define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d)-1) / (d))
#endif
#define DIV_ROUND_UP __KERNEL_DIV_ROUND_UP

#ifndef __KERNEL__
void* ERR_PTR(long error);
#define ffs(x) __builtin_ffs(x)
int           fls(unsigned int x);
unsigned long __fls(unsigned long word);
unsigned long __ffs(unsigned long word);
int           fls64(uint64_t x);
#endif

#define assert(x)                              \
    do {                                       \
        if (!x) mpi_log("failed assertion\n"); \
    } while (0);

/* If KARATSUBA_THRESHOLD is not already defined, define it
 * to a value which is good on most machines.  */

/* tested 4, 16, 32 and 64, where 16 gave the best
 * performance when checking a 768 and a 1024 bit ElGamal
 * signature. (wk 22.12.97) */
#ifndef KARATSUBA_THRESHOLD
#define KARATSUBA_THRESHOLD 16
#endif

/* The code can't handle KARATSUBA_THRESHOLD smaller than 2.
 */
#if KARATSUBA_THRESHOLD < 2
#undef KARATSUBA_THRESHOLD
#define KARATSUBA_THRESHOLD 2
#endif

typedef mpi_limb_t* mpi_ptr_t;  /* pointer to a limb */
typedef int         mpi_size_t; /* (must be a signed type) */

#define RESIZE_IF_NEEDED(a, b)                        \
    do {                                              \
        if ((a)->alloced < (b)) mpi_resize((a), (b)); \
    } while (0)

/* Copy N limbs from S to D.  */
#define MPN_COPY(d, s, n)                               \
    do {                                                \
        mpi_size_t _i;                                  \
        for (_i = 0; _i < (n); _i++) (d)[_i] = (s)[_i]; \
    } while (0)

#define MPN_COPY_INCR(d, s, n)                          \
    do {                                                \
        mpi_size_t _i;                                  \
        for (_i = 0; _i < (n); _i++) (d)[_i] = (s)[_i]; \
    } while (0)

#define MPN_COPY_DECR(d, s, n)                             \
    do {                                                   \
        mpi_size_t _i;                                     \
        for (_i = (n)-1; _i >= 0; _i--) (d)[_i] = (s)[_i]; \
    } while (0)

/* Zero N limbs at D */
#define MPN_ZERO(d, n)                            \
    do {                                          \
        int _i;                                   \
        for (_i = 0; _i < (n); _i++) (d)[_i] = 0; \
    } while (0)

#define MPN_NORMALIZE(d, n)        \
    do {                           \
        while ((n) > 0) {          \
            if ((d)[(n)-1]) break; \
            (n)--;                 \
        }                          \
    } while (0)

#define MPN_MUL_N_RECURSE(prodp, up, vp, size, tspace) \
    do {                                               \
        if ((size) < KARATSUBA_THRESHOLD)              \
            mul_n_basecase(prodp, up, vp, size);       \
        else                                           \
            mul_n(prodp, up, vp, size, tspace);        \
    } while (0);

/* Divide the two-limb number in (NH,,NL) by D, with DI
 * being the largest limb not larger than
 * (2**(2*BITS_PER_MP_LIMB))/D - (2**BITS_PER_MP_LIMB). If
 * this would yield overflow, DI should be the largest
 * possible number (i.e., only ones).  For correct
 * operation, the most significant bit of D has to be set.
 * Put the quotient in Q and the remainder in R.
 */
#define UDIV_QRNND_PREINV(q, r, nh, nl, d, di)        \
    do {                                              \
        mpi_limb_t _ql;                               \
        mpi_limb_t _q, _r;                            \
        mpi_limb_t _xh, _xl;                          \
        umul_ppmm(_q, _ql, (nh), (di));               \
        _q += (nh); /* DI is 2**BITS_PER_MPI_LIMB too \
                       small */                       \
        umul_ppmm(_xh, _xl, _q, (d));                 \
        sub_ddmmss(_xh, _r, (nh), (nl), _xh, _xl);    \
        if (_xh) {                                    \
            sub_ddmmss(_xh, _r, _xh, _r, 0, (d));     \
            _q++;                                     \
            if (_xh) {                                \
                sub_ddmmss(_xh, _r, _xh, _r, 0, (d)); \
                _q++;                                 \
            }                                         \
        }                                             \
        if (_r >= (d)) {                              \
            _r -= (d);                                \
            _q++;                                     \
        }                                             \
        (r) = _r;                                     \
        (q) = _q;                                     \
    } while (0)

/*-- mpiutil.c --*/
mpi_ptr_t mpi_alloc_limb_space(unsigned nlimbs);
void      mpi_free_limb_space(mpi_ptr_t a);
void      mpi_assign_limb_space(MPI a, mpi_ptr_t ap, unsigned nlimbs);

static inline mpi_limb_t mpihelp_add_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
                                       mpi_size_t s1_size, mpi_limb_t s2_limb);
mpi_limb_t mpihelp_add_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_ptr_t s2_ptr,
                         mpi_size_t size);
static inline mpi_limb_t mpihelp_add(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
                                     mpi_size_t s1_size, mpi_ptr_t s2_ptr,
                                     mpi_size_t s2_size);

static inline mpi_limb_t mpihelp_sub_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
                                       mpi_size_t s1_size, mpi_limb_t s2_limb);
mpi_limb_t mpihelp_sub_n(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr, mpi_ptr_t s2_ptr,
                         mpi_size_t size);
static inline mpi_limb_t mpihelp_sub(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
                                     mpi_size_t s1_size, mpi_ptr_t s2_ptr,
                                     mpi_size_t s2_size);

/*-- mpih-cmp.c --*/
int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size);

/*-- mpih-mul.c --*/

struct karatsuba_ctx {
    struct karatsuba_ctx* next;
    mpi_ptr_t             tspace;
    mpi_size_t            tspace_size;
    mpi_ptr_t             tp;
    mpi_size_t            tp_size;
};

void mpihelp_release_karatsuba_ctx(struct karatsuba_ctx* ctx);

mpi_limb_t mpihelp_addmul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
                            mpi_size_t s1_size, mpi_limb_t s2_limb);
mpi_limb_t mpihelp_submul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
                            mpi_size_t s1_size, mpi_limb_t s2_limb);
int  mpihelp_mul(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t usize, mpi_ptr_t vp,
                 mpi_size_t vsize, mpi_limb_t* _result);
void mpih_sqr_n_basecase(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size);
void mpih_sqr_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t size,
                mpi_ptr_t tspace);
void mpihelp_mul_n(mpi_ptr_t prodp, mpi_ptr_t up, mpi_ptr_t vp,
                   mpi_size_t size);

int mpihelp_mul_karatsuba_case(mpi_ptr_t prodp, mpi_ptr_t up, mpi_size_t usize,
                               mpi_ptr_t vp, mpi_size_t vsize,
                               struct karatsuba_ctx* ctx);

/*-- generic_mpih-mul1.c --*/
mpi_limb_t mpihelp_mul_1(mpi_ptr_t res_ptr, mpi_ptr_t s1_ptr,
                         mpi_size_t s1_size, mpi_limb_t s2_limb);

/*-- mpih-div.c --*/
mpi_limb_t mpihelp_mod_1(mpi_ptr_t dividend_ptr, mpi_size_t dividend_size,
                         mpi_limb_t divisor_limb);
mpi_limb_t mpihelp_divrem(mpi_ptr_t qp, mpi_size_t qextra_limbs, mpi_ptr_t np,
                          mpi_size_t nsize, mpi_ptr_t dp, mpi_size_t dsize);
mpi_limb_t mpihelp_divmod_1(mpi_ptr_t quot_ptr, mpi_ptr_t dividend_ptr,
                            mpi_size_t dividend_size, mpi_limb_t divisor_limb);

/*-- generic_mpih-[lr]shift.c --*/
mpi_limb_t mpihelp_lshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
                          unsigned cnt);
mpi_limb_t mpihelp_rshift(mpi_ptr_t wp, mpi_ptr_t up, mpi_size_t usize,
                          unsigned cnt);

/* Define stuff for longlong.h.  */
#define W_TYPE_SIZE BITS_PER_MPI_LIMB
typedef mpi_limb_t   UWtype;
typedef unsigned int UHWtype;
#if defined(__GNUC__)
typedef unsigned int UQItype __attribute__((mode(QI)));
typedef int          SItype __attribute__((mode(SI)));
typedef unsigned int USItype __attribute__((mode(SI)));
typedef int          DItype __attribute__((mode(DI)));
typedef unsigned int UDItype __attribute__((mode(DI)));
#else
typedef unsigned char UQItype;
typedef long          SItype;
typedef unsigned long USItype;
#endif

#ifdef __GNUC__
#include "mpi-inline.h"
#endif

#endif /*G10_MPI_INTERNAL_H */
